Is Java in Your Future? - MD ColdFusion User's Group

Transcript Is Java in Your Future? - MD ColdFusion User's Group

MDCFUG
Is Java in Your Future?
Tyler Williams
Principal Consultant @ dataTerrace
[email protected]
Agenda
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The Java Learning Curve
Why This is a Good Thing
J2EE Breakdown
Sample Program
Q&A
My Background
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Consultant 2 1/2 years
Certified CF Developer
4 years CF
1 year Java
6 years Oracle
Java Language Barriers
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Non-Tag Based
Lower Level Than CF (more code)
Object Oriented
Strongly Typed & Case Sensitive
Large “Function Library”
Powerful, Complex and Less Forgiving
Power of Perception
• CF is Easy to Learn
• Ease of Entry Brings Less Qualified
Programmers to the Language
• More Low Grade Programs are Written
• CF Language Gets a Bad Rap
The Good Side of Barriers
• Less Competition
• Higher Rates
• Protected Reputation
J2EE - Enterprise Java
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Server-side Web Development
Standard Created by Sun
Many Competing Application Servers
App Servers Must Pass a Compatibility
Test Suite
• Vendors Add Extensions & JSP Tag
Libraries
J2EE Technologies
• Lower Complexity
– Java Server Pages (JSP)
– Servlets
• Higher Complexity
– JDBC (Database Connectivity)
– Enterprise Java Beans (EJB)
– Java Messaging Service (JMS)
JSP Example
<%@ page info="Simple JSP Page example" %>
<%
String str = "8th";
%>
<html>
<head><title>Simple JSP Page</title></head>
<body bgcolor="#ffffff">
<h1>Welcome to the <%=
</body>
</html>
str %> dimension</h1>
Servlet Example
import java.io.*;
import servlet.*;
import servlet.http.*;
public class SimpleServlet extends HttpServlet {
public void doGet (HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
response.setContentType(“text/html”);
PrintWriter out = response.getWriter();
out.println(“<html><head><title>Simple Servlet Example</title></head>”);
out.println(“<body bgcolor="#ffffff">”);
String str = "8th";
out.println(“<h1>Welcome to the ” + str
out.println(“</body></html>”);
}
}
+ “ dimension</h1>”);
JDBC Example
Class.forName("oracle.jdbc.driver.OracleDriver");
String stUrl_= "jdbc:oracle:thin:@host:1521:sid";
Connection connection_ = DriverManager.getConnection(stUrl_, ”username",”password");
PreparedStatement statement_ = connection_.prepareStatement("SELECT fname, lname
FROM EMPLOYEE");
ResultSet rs = statement_.executeQuery(); //execute query
while (rs.next()) {
String firstName = rs.getString(1);
String lastName = rs.getString(2);
strOut = strOut + firstName + " " + lastName + "<BR>";
}
rs.close();
statement_.close();
connection_.close();
CF Comparison
<cfquery name="main_select" datasource="MYDS">
SELECT fname, lname FROM EMPLOYEE
</cfquery>
<cfoutput query="main_select">
#main_select.fname# #main_select.lname#
</cfoutput>
JDBC Metadata
• getColumnCount - Returns the number of
columns in this Result Set
• getColumnName - Get the designated
column's name
• getColumnType - Retrieve the designated
column's SQL type
• isAutoIncrement - Indicates whether the
designated column is automatically numbered, thus
read-only
Model-View-Controller (MVC)
• Model = Data = JDBC
• View = Presentation = JSP
• Controller = Framework = Servlet
MVC Flow
1) Client submits a page request
Client
2) Servlet interprets request
Servlet
JSP
JDBC
3) Servlet retrieves necessary
info from JDBC
4) Servlet hands off request and
details to JSP for formatting and
presentation
Complete MVC Example
• DimensionApp.java (Servlet)
• DimensionVO.java (JDCB Class)
• Display.jsp (JSP)
DimensionApp.java
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import DimensionVO;
public class DimensionApp extends HttpServlet {
public void service (HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
DimensionVO dvo = new DimensionVO();
String mydim = dvo.getDimension();
req.setAttribute("dimension", mydim);
RequestDispatcher rd;
rd = getServletContext().getRequestDispatcher("/jsp/Display.jsp");
rd.forward(req, res);
}
}
DimensionVO.java
import java.sql.*;
import java.util.*;
import java.io.*;
public class DimensionVO {
String strOut;
String stUrl_= "jdbc:odbc:mdcfug";
private Connection connection_ = null;
private PreparedStatement statement_ = null;
private ResultSet rs;
public String getDimension ()
throws IOException {
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection connection_ = DriverManager.getConnection(stUrl_, "Admin","");
statement_ = connection_.prepareStatement("SELECT dimension FROM DIMENSIONS");
rs = statement_.executeQuery(); //execute query
String mydim = rs.getString(1);
strOut = mydim;
rs.close();
statement_.close();
connection_.close();
}
catch (ClassNotFoundException e) {// Shouldn't happen - it comes with the JRE}
catch (SQLException e) {System.err.println("Unable to connect to the DB " + e);}
return strOut;
}
}
Display.jsp
<%@ page info="MVC Example" %>
<%String str = (String)request.getAttribute("dimension");%>
<html>
<head><title>MVC Example</title></head>
<body bgcolor="#ffffff">
<table>
<tr>
<td width=150>   </td>
<td width=250 align=right> <h1>Welcome to the <%= str %> dimension</h1> </td>
</tr>
</table>
</body>
</html>
Java Resources
• Java’s Home @ Sun
– http://java.sun.com
• Java Portals
– http://www.theserverside.com
– http://www.jguru.com/
• Sun’s JDBC Tutorial
– http://developer.java.sun.com/developer
/onlineTraining/Database/JDBC20Intro/
Java Bookshelf
• The Java Language
– Java in a Nutshell - Flanagan
• Servlets/JSP
– Java Servlet Programming - Hunter
– Web Development With JavaServer Pages Fields/Kolb
– Core Servlets and JavaServer Pages - Hall
• J2EE Application Architecture
– Core J2EE Patterns - Alur

Is Java in Your Future? - MD ColdFusion User's Group

Transcript Is Java in Your Future? - MD ColdFusion User's Group

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